This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Description: My lab studies the structure and function of voltage-gated calcium channels from the human blood fluke, Schistosoma mansoni, a platyhelminth parasite that causes schistosomiasis. Our results from heterologous expression of schistosome calcium channel subunits indicate that they are targets of praziquantel, the current drug of choice against schistosomiasis. Further research will probe the precise mechanism by which praziquantel acts, using single channel recordings of expressed channel subunits in mammalian cells. We also study the function and pharmacology of schistosome multidrug resistance proteins and their interaction with praziquantel. These transporter proteins mediate efflux of wastes and xenobiotics, making them potentially powerful drug targets, and may also be involved in resistance to praziquantel.